Michael Phelps‘ world record in his signature event was emphatically wiped away by 19-year-old Hungarian Kristof Milak at the world championships in Gwangju, South Korea on Wednesday.

Milak clocked 1:50.73, taking .78 off Phelps’ mark from the 2009 World Championships, where since-banned high-tech swimsuits contributed to a bevy of fast times.

“As frustrated as I am to see that record go down, I couldn’t be happier to see how he did it,” Phelps said after watching the race online, according to The New York Times. “That kid’s last 100m was incredible. He put together a great 200 fly from start to finish.”

Phelps held the world record since 2001, his streak of 18 years the longest for one men’s event in swimming history, according to Olympic historians Bill Mallon and Hilary Evans.

Milak was a backstroker until age 14, but even when he devoted to the butterfly, he focused on the 100m because he lacked strength. Milak broke out in 2018 by lowering his 200m personal best to 1:52.71, the sixth-fastest time in history behind four from Phelps and one from countryman Laszlo Cseh.

“I tried to switch off everything, and I tried not to think of swimming at all before the race,” he said. “It’s a tremendous honor to set such a great record.”

Phelps won eight combined Olympic and world titles in the 200m fly, the event where he made his Olympic debut in 2000 (placing fifth).

Phelps broke his first of 39 world records across all events in the 200m fly in March 2001 at a meet where he listened to “Perfect Gentleman” by Wyclef Jean on a CD player on repeat before races. At 15, Phelps was the youngest man to break a world record.

He won his first world title in the 200m fly, later in 2001, and lowered the world record eight times overall.

Phelps, who retired after his record 28th Olympic medal in Rio and has brushed off comeback questions for the last three years, still owns world records in the 100m butterfly and 400m individual medley.

Milak became the first man to break a Phelps world record since Milorad Cavic took the 100m fly mark at the 2009 Worlds, where Phelps snatched the record back the following day.

Also Wednesday, Caeleb Dressel‘s bid for a Phelps-record-breaking eight golds at a single worlds may have ended as Australia edged the U.S. by .02 in the mixed-gender 4x100m medley. Dressel made up a 7.21-second deficit on the third leg, the butterfly, because two women and two men were scattered across the four spots for each team. But Australian Cate Campbell made up a 1.25-second deficit on Simone Manuel on anchor.

Dressel matched Phelps’ record seven golds at a single worlds two years ago with the help of two mixed-gender relays that weren’t on the program in Phelps’ heyday. Dressel can still get to seven as he’s expected to race in five more finals this week, but to reach eight, he must be added to the men’s 4x200m free, which he was not part of in 2017.

Controversial Chinese Sun Yang was sixth in the 800m freestyle, a final that went off without an American for the first time in 12 years. Italian Gregorio Paltrinieri, the Olympic 1500m champion, prevailed by 2.01 seconds in 7:39.27.

Sun won the 800m in 2011, 2013 and 2015 but has in recent years shifted toward the 200m and 400m frees, which he won earlier this week and faced podium protests from Australian and British medalists. The 800m marked the last individual event for Sun at this meet.

Italian Federica Pellegrini earned her fourth world title in the 200m free and her eight straight medal dating to 2005. Pellegrini, a 30-year-old who next year will be older than any individual female Olympic swimming champion, surged past 18-year-old Australian Ariarne Titmus in the last 50 meters to win by .44 in 1:54.22.

Two years ago, Pellegrini handed Katie Ledecky her first major international final loss in any individual event. Ledecky, plus medal contenders Emma McKeon of Australia and Taylor Ruck of Canada, withdrew before Tuesday’s 200m free heats, with Ledecky and McKeon citing illness. Ledecky was still under the weather on Wednesday, dampening her hopes of starting her last two events of the meet — Thursday’s 4x200m free and the 800m free Friday and Saturday.

Brit Adam Peaty completed a sweep of the 50m and 100m breaststrokes for a third straight worlds, clocking 26.06 seconds. Peaty owns the seven fastest times in history in the non-Olympic event, including the world record of 25.95.

Katie Ledecky routed the 1500m freestyle field by 21.11 seconds as the U.S. won seven of 10 events on the last day of the Pan Pacific Championships in Tokyo on Sunday.

Ledecky ended the meet with three gold medals, one silver and one bronze. In her last swim, she clocked 15:38.97, well off her world record from May 16 of 15:20.48, but still easily enough to win an event that she has never lost.

“The time wasn’t great,” Ledecky told media in Tokyo. “Swimming the range of events that I swim, it’s hard to put together all great races.”

She qualified for the 2019 World Championships in the 200m, 400m, 800m and 1500m frees and also figures to anchor the 4x200m free relay in South Korea next year. Ledecky swam all of those events plus the 4x100m free at the 2017 Worlds.

Sweeping those five events at 2019 Worlds, as she did at the 2015 Worlds, looks like a difficult task. Ledecky was third in the 200m free in Tokyo, faced (and passed) her toughest test in the 400m free in six years and was part of a 4x200m free team at Pan Pacs that was beaten by Australia.

Overall, many U.S. swimmers posted slower times than they did at nationals two weeks ago, some citing jet lag from arriving in Japan four days before the meet started. The Americans won two of the seven relays, its worst percentage at a major international meet since it went winless at the 2001 Worlds.

Australia swept the women’s relays, capped by Cate Campbell passing Olympic and world 100m free champion Simone Manuel on the last leg of the medley relay Sunday. The U.S. barely held off Japan by .05 in the men’s medley relay, one day after swimming out of order in the 4x100m free.

The U.S. totaled 18 gold medals for the meet, which does not include European nations and lacks China’s best swimmers. Australia was second at eight golds with open-water events still to come.

In other events Sunday, Michael Andrew upset seven-time 2017 World champion Caeleb Dressel in the 50m freestyle for a second straight meet. Andrew, who turned pro at 14 in 2013, clocked a personal-best 21.46 seconds, easily beating Dressel (21.93). Great Britain’s Ben Proud is fastest in the world this year at 21.11.

“The first two finals sessions [this week] were kind of rough,” said Andrew, who clocked personal bests in the 50m free, 100m backstroke and 100m butterfly in Tokyo. “I feel like that had to do with maybe time zone or something. But very quickly I took the effort, changing my mental frame of mind, being able to prepare for the meet I still had ahead of me. So I’m really happy with the swims.”

Campbell completed a sweep of the sprint freestyles, holding off Manuelin the 50m free. Campbell clocked 23.81 to Manuel’s 24.22 and finished the meet with five golds, including three on relays.

Olympic champion Ryan Murphy won the 200m backstroke in a personal-best 1:53.57, ranking him second in the world this year behind world champion Evgeny Rylov of Russia.

Zane Grothe missed the American record by .14, winning the 800m freestyle in 7:43.74. Grothe, who made the 2019 Worlds team in the 400m, 800m and 1500m frees, ranks second in the world this year behind European champion Mykhailo Romanchuk of Ukraine.

Kathleen Baker took the women’s 200m back in a personal-best 2:06.14, ranking her second in the world this year. World leader Kylie Masse of Canada was fourth in 2:07.00.

In the 200m breaststroke, Micah Sumrall edged Olympic 100m breast champion Lilly King by .24 in 2:21.88. King’s rival in the 100m breast, Russian Yulia Efimova, owns the fastest time in the world this year of 2:20.72.

World-record holder Ippei Watanabe of Japan won the men’s 200m breast in 2:07.75. World champion Anton Chupkov of Russia is fastest in the world this year with a 2:06.80.

The U.S. has dominated swimming since the heyday of its rivalry with Australia more than a decade ago, but the Aussies had one of their biggest recent gold-medal sweeps at the expense of the Americans on Friday.

Cate Campbell and Kyle Chalmers won the 100m freestyles at the Pan Pacific Championships, the biggest international meet for U.S. swimmers this year, in Tokyo.

The Aussies also beat the U.S. in the 4x200m free relay, with Madeline Groves holding off Katie Ledecky on anchor.

Groves was given a 2.88-second lead and edged Ledecky by .25, marking the American women’s first loss in a major international meet since 2009 Worlds.

Ledecky had the fastest split of the relay — 1:53.84 — which was .28 faster than Canadian Taylor Ruck, who won the individual 200m free over Ledecky on Thursday.

U.S. leadoff Allison Schmitt had the slowest leg of the 16 total swimmers — 1:58.62 — the slowest by an American woman in a 4x200m free final at a major meet since 2010, though leadoff legs are slowed by reaction time.

The U.S. men held off Australia in the 4x200m free, with Townley Haas touching .24 ahead of Jack Cartwright.

Campbell clocked the second-fastest time ever — 52.03 seconds — to hand Simone Manuel her first loss in a major international 100m free in three years. Manuel, a distant runner-up in 52.66, shared the 2016 Olympic title with Canadian Penny Oleksiak and took the 2017 World title outright.

“I definitely was disappointed with losing, but I think I’m more disappointed with my time,” said Manuel, who was .12 faster at nationals two weeks ago.

Campbell entered the Rio Games as the world-record holder but was a disappointing sixth in Brazil, later saying she swam with a hernia. The 26-year-old skipped the 2017 Worlds but stormed back this year, clocking 52.37 in March, good for No. 2 in the world going into Pan Pacs.

“I can put to bed all the nightmares and thoughts that come creeping in when you’re lying awake, stewing over past performances,” Campbell said, according to the Sydney Morning Herald. “I swam a personal best. These don’t come around very often at my age. I couldn’t be happier.”

Chalmers, the surprise Rio Olympic 100m free champion, pulled off another upset to take the Pan Pacs title. He touched in 48.00, beating world champion Caeleb Dressel and fellow Aussie Cartwright by .22.

Chalmers, 20, entered the final with the fifth-fastest time this year among the eight racers. He missed the 2017 Worlds after undergoing heart surgery and was third at the Commonwealth Games on April 8.

“I was beginning to doubt myself that little bit in the 100m,” Chalmers said, according to the Sydney Morning Herald. “I haven’t done a whole lot of 100m work, but I’m a competitor.”

Australia bagged as many gold medals Friday at Pan Pacs — a meet without European nations and top stars from China and South Africa — as it did in all swim events at the Rio Olympics. The Aussies won a single gold at the 2017 Worlds.

Dressel dominated the 100m free at 2017 Worlds, winning in an American record 47.17 seconds as one of his Michael Phelps-record-tying seven gold medals at the meet.

He was sixth at the U.S. Championships two weeks ago in what coach Gregg Troy said was the worst thing that’s happened to him in the pool in four years since matriculating at the University of Florida.

“Pretty far off my best,” Dressel said Friday. “It’s been a little bit of a hectic year [Dressel finished his college career and turned pro in the last six months]. It was a learning year. Pan Pacs is a little more low key than worlds and Olympics. It’s just been a little crazy. That’s all right for right now.”

Dressel managed a different kind of victory Friday, grabbing one of two spots on the U.S. team in the 100m free for the 2019 World Championships, along with U.S. champion Blake Pieroni.

That means Nathan Adrian will not contest a 100m free at a major international meet for the first time since he was a prelim relay swimmer at the 2008 Olympics.

Also Friday, Rio gold medalist Ryan Murphy won the 100m backstroke in 51.94, just .09 off his world record. The race lacked world champion Xu Jiayu as China is saving its best swimmers for the Asian Games later this month.

World champion Kylie Masse of Canada captured the women’s 100m back in 58.61, .11 ahead of 2015 World champion Emily Seebohm of Australia. American Kathleen Baker, who at nationals broke Masse’s world record, earned bronze.

U.S. Olympian Hali Flickinger won the 200m butterfly in 2:07.35. Flickinger ranks second in the world this year with her 2:05.87 from nationals.

Japan’s Daiya Seto took the men’s 200m fly in 1:54.34, ranking him fifth in the world this year. The top American was Zach Harting in third in 1:55.05.